基于云服务的分布式嵌入式设备时间同步研究——以智能停车诱导系统为例

Research on Time Synchronization of Embedded Devices Based on Cloud Services--Taking Intelligent Parking Guidance System as an Example

智能停车诱导系统是智慧城市建设的组成部分。通常由信息采集、云服务中心处理和信息呈现三个模块组成,信息采集模块和信息呈现模块大多是嵌入式设备。停车诱导系统中,分布式嵌入式设备与云服务器之间的时间同步至关重要,直接影响着停车诱导结果是否准确。在系统中引入时间同步算法,嵌入式设备基于MQTT协议向云服务器订阅时间同步服务,申请与服务器时间同步。在算法中对异常情况加入去掉噪音数据和重试机制,经过实验分析,时间同步达到毫秒级的要求,为系统提供更可靠的时间保障,提升停车诱导结果的准确性。

Intelligent parking guidance system is an integral part of smart city construction.Parking guidance system consists of three modules:information collection,cloud service center processing and information presentation.Most of the information collection modules and information presentation modules are embedded devices.In parking guidance system,time synchronization between distributed embedded devices and cloud server is very important,which directly affects the accuracy of parking guidance results.The time synchronization algorithm is introduced in the system,and the embedded device subscribes to the time synchronization service of the cloud server based on the MQTT protocol to apply for time synchronization with the server.In the algorithm,the noise data removal and retrial mechanism are added to the abnormal situation.Through the experimental analysis,the time synchronization reaches the requirement of millisecond level,which provides more reliable time for the intelligent parking guidance system and improves the accuracy of the parking guidance results.